1. Field of the Invention
The present invention relates to a thin-film magnetic head for perpendicular magnetic recording which is used to record information on a recording medium by the perpendicular magnetic recording method, and also to a method for manufacturing the same.
2. Description of the Related Art
There are two ways to record information using the thin-film magnetic head: longitudinal recording in which the magnetization directions of data bits are parallel (longitudinal) to the plane of the recording medium, and perpendicular recording in which the magnetization directions of data bits are perpendicular to the plane of the recording medium. Advantages of perpendicular recording are that the recording medium holding information is less vulnerable to thermal fluctuation, and that it can realize high recording density.
As prior arts in the magnetic recording technology of perpendicular recording, there are U.S. Pat. No. 6,504,675 and U.S. Pat. No. 4,672,493, for example.
As to the thin-film magnetic head for perpendicular recording, however, there is a problem of the pole erasure phenomenon that, while write operation of information is at rest, a residual magnetic field in the magnetic head generated during the write operation leaks out toward the recording medium and erroneously erases the information already recorded thereon.